Appliances or systems which are adapted to be connected to fresh water pipes are normally provided with means to prevent reverse flow of water into the water pipes. Commercial dishwashers, for example, are required to include a vacuum breaker in the water inlet line so that water cannot be siphoned from the washer into a fresh water system. Although various types of vacuum breakers are possible, it is common to employ a vertical fitting with an opening in a side thereof through which air may pass. Unfortunately, water can and does splash through such an opening so that an operator is at least tempted to block the opening and thus defeat the protection required.
Considering further the field of commercial dishwashers it is noted that various chemicals, at least including a detergent, are inserted in wash water thereof in some automatic manner. Commonly, one or more holes are drilled in the wash chamber and the detergent and other chemicals inserted therethrough so as to fall into the wash tank for mixing with the wash water. This may not insure an even dispersal of a correct concentration of chemicals in the water at all times. While it is known to meter chemicals into the inflowing water for washing or rinsing, it is necessary to employ a vacuum breaker in the water line ahead of the addition.
The present invention provides a combined mixing chamber for mixing metered amounts of chemicals into incoming water and a vacuum breaker or air gap preventing water splashing or leakage from the system.